make gm self-tests launch python unittests automatically

gm/rebaseline_server/base_unittest.py

 #!/usr/bin/python
 
 """
 Copyright 2014 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 A wrapper around the standard Python unittest library, adding features we need
 for various unittests within this directory.
 """
 
 import filecmp
 import os
 import shutil
 import tempfile
 import unittest
 
 PARENT_DIR = os.path.dirname(os.path.realpath(__file__))
 TRUNK_DIR = os.path.dirname(os.path.dirname(PARENT_DIR))
 TESTDATA_DIR = os.path.join(PARENT_DIR, 'testdata')
 OUTPUT_DIR_ACTUAL = os.path.join(TESTDATA_DIR, 'outputs', 'actual')
 OUTPUT_DIR_EXPECTED = os.path.join(TESTDATA_DIR, 'outputs', 'expected')
 
 
 class TestCase(unittest.TestCase):
 
   def setUp(self):
+    # Get the name of this test, in such a way that it will be consistent
+    # regardless of the directory it is run from (throw away package names,
+    # if any).
+    test_name = '.'.join(self.id().split('.')[-3:])
+
     self._input_dir = os.path.join(TESTDATA_DIR, 'inputs')
-    self._output_dir_actual   = os.path.join(OUTPUT_DIR_ACTUAL, self.id())
-    self._output_dir_expected = os.path.join(OUTPUT_DIR_EXPECTED, self.id())
+    self._output_dir_actual   = os.path.join(OUTPUT_DIR_ACTUAL, test_name)
+    self._output_dir_expected = os.path.join(OUTPUT_DIR_EXPECTED, test_name)
     create_empty_dir(self._output_dir_actual)
     self._temp_dir = tempfile.mkdtemp()
 
   def tearDown(self):
     shutil.rmtree(self._temp_dir)
     if os.path.exists(self._output_dir_expected):
       different_files = find_different_files(self._output_dir_actual,
                                              self._output_dir_expected)
       # Maybe we should move this assert elsewhere?  It's unusual to see an
       # assert within tearDown(), but my thinking was:
@@ skipping 76 matching lines @@
   differing_files.extend(dircmp.funny_files)
   for common_dir in dircmp.common_dirs:
     differing_files.extend(find_different_files(
         os.path.join(dir1, common_dir), os.path.join(dir2, common_dir)))
   return differing_files
 
 
 def main(test_case_class):
   """Run the unit tests within the given class."""
   suite = unittest.TestLoader().loadTestsFromTestCase(test_case_class)
-  results = unittest.TextTestRunner(verbosity=2).run(suite)
+  unittest.TextTestRunner(verbosity=2).run(suite)